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Computational Thermodynamics

Byeong-Joo Lee Computational Materials Science & Engineering Lab. Pohang University of Science & Technology. Computational Thermodynamics. R&D in Materials Science and Engineering. Structure Evolution. Materials Property. Process Condition.

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Computational Thermodynamics

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  1. Byeong-Joo Lee Computational Materials Science & Engineering Lab.Pohang University of Science & Technology Computational Thermodynamics

  2. R&D in Materials Science and Engineering Structure Evolution Materials Property Process Condition Research Type I : experiments first, then thinking Research Type II: think first, then do experiments

  3. ThermodynamicModelling

  4. Lattice Stability

  5. Regular Solution vs. Quasi-Chemical Model

  6. Thermodynamic Assessment – Cr-Ni Binary System LfccCr,Ni = 8030 – 12.8801·T + (33080 – 16.0362·T)(1-2XNi) LbccCr,Ni = 17170 – 11.8199·T + (34418 – 11.8577·T)(1-2XNi) LliqCr,Ni = 318 – 7.3318·T + (16941 – 6.3696·T)(1-2XNi) B.-J. Lee, 1992

  7. Thermodynamic Assessment – Fe-Cr-Ni Ternary System B.-J. Lee 1993

  8. Thermodynamic Parameters (Fe,Cr,Mo)(Va,B,C,N)

  9. Thermodynamic Modeling – Gibbs Energy For a Phase with Formula Unit, (M1,M2,…,Mi,…)a(Va,C,N)c

  10. Thermodynamic Modeling – Gibbs Energy For a Phase with Formula Unit, (M1,M2,…,Mi,…)a(Va,C,N)c

  11. Thermodynamic Database for Steels –TCFe2000 → TCFe2 → TCFe3 Fe-Cr-Ni-Mo-Mn-Si-C-N +Nb-Ti-V-W-Al-Co-Cu-B-O-P-S 8C2 = 28 Binary Systems8C3 = 56 Ternary Systems19C2 = 171 Binary Systems19C3 = 969 Ternary Systems

  12. Solution Models - liquid and fcc Fe-C alloys

  13. Solution Model - liquid and fcc Fe-C alloys fcc : (Fe)1(Va,C) 1 Liquid : (Fe,C) Ternary (Fe,Mn)a(Va,C) c

  14. Applications ofComputational Thermodynamics

  15. Thermodynamic Calculation – Practical Steels

  16. Computational Thermodynamics의 적용 분야 Structural Materials (Steel, Solder, Al-, Ti-, Ni-, Mg-alloys), Semiconducting Materials, Ceramic Materials, Hydrogen Storage Materials, CVD process 등 열역학이 지배하는 모든 물질계 Thermodynamic Calculation – Application to Alloy Design

  17. Thermodynamic Calculation – Application to Alloy/Process Design AB1: 0.1C-5MN-7Al AB2: 0.2C-4Mn-6.6Al AB3: 0.3C-3.5Mn-6Al AB4: 0.4C-3.5Mn-5.8Al AB5: 0.5C-3Mn-4.9Al AB6: 0.3C-4Mn-7.3Al-0.05Ti

  18. Thermodynamics Assessment - Na-Al-H system

  19. Assessment of thermodynamic properties in the Li-Al-H ternary system

  20. Driving force of CVD Deposition ※ Example: Deposition of Silicon SiH4 + 2Cl2 = Si + 4HCl

  21. Interfacial Reactions

  22. Interfacial Reaction between Cu and Various Solder • Experimental Observation •    ▶ Cu/Sn : Cu6Sn5 •    ▶ Cu/Sn-Pb eutectic : Cu6Sn5 •    ▶ Cu/Sn-Ag eutectic : Cu6Sn5 •    ▶ Cu/Sn-Zn eutectic : CuZn_γ •    ▶ Cu/Sn-In eutectic : Cu2(Sn,In) or Cu2In3Sn

  23. Application to Solder/Substrate Interfacial Reactions – Cu/Sn Reaction

  24. Application to Solder/Substrate Interfacial Reactions – Cu/Sn Reaction

  25. Application to Thin Film Reactions – Metal/Si Reaction

  26. Application to Thin Film Reactions – Metal/Si Reaction

  27. Application to Thin Film Reactions – Metal/Si Reaction

  28. Application to Thin Film Reactions – Metal/Si Reaction

  29. Application to Interfacial Reactions – Metal/Si Reaction

  30. Computational Materials Science & Engineering Lab.Pohang University of Science & Technology, Korea Thermodynamics Nano Materials Eunha Kim Inyoung Sa Byeong-Moon Lee and Byeong-Joo Lee

  31. Curvature Effect– Capillary Pressure System condition T = constant Vα = Vβ = V = constant @ equilibrium

  32. Curvature Effect– Capillary Pressure Effect on Melting Point of Nano Particle

  33. Melting points of Gold Nano Particles: B-J Lee, 2009

  34. Melting points of Nano Particles: B-J Lee, 2009 Pt Ni Au W Mg Pt

  35. Melting points of Nano Wires: B-J Lee, 2009 Ni Pt Au W Mg Pt

  36. Motivation- in Collaboration with M.-H. Jo, POSTECH

  37. Vapor-Liquid Liquid-Solid SiH4 + GeH4 + H2 ① ② Reactions during the VLS Process

  38. Vapor-Liquid Liquid-Solid SiH4 + GeH4 + H2 ① ① ② ② Reactions during the VLS Process 200 torr 400 oC

  39. VLS Growth of Nanowires - GeSi Nanowires

  40. Size dependence of SiGe nanowire composition

  41. Size dependence of SiGe nanowire composition CALPHAD (2008)

  42. Interfacial Phenomena – Segregation (Guttmann, Butler/Tanaka) Assume a one atomic layer surface phase and consider equilibrium between bulk and surface where ωi is the molar surface area Assume ωi = ωj = … = ω

  43. Calculation of Surface Tension of Liquid Alloys

  44. Calculation of Surface Segregation in Solid Alloys

  45. Computational Thermodynamics as Materials Genome Computational Thermodynamics + First-Principles Calculation

  46. Application to Metal/Ceramics Interfacial Reactions – Ti/Al2O3 Reaction

  47. Application to Metal/Ceramics Interfacial Reactions – Ti/Al2O3 Reaction

  48. Phase Field Simulation of γ→α transformation in steels Wetting angle : 36o Wetting angle : 120o Fe - 0.5% Mn – 0.1% C, dT/dt = 1 oC/s from SG Kim, Kunsan University

  49. Summary Computational Thermodynamics • Calculation of Multi-component Phase Diagrams • Interfacial Reactions • – Metal/Liquid Solder, Metal/Ceramics • Thin Films Reactions • – Metal/Silicon • Thermodynamics of Nano Materials • – Capillarity Effect

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